Clinical application of viscoelastic point-of-care tests of coagulation-shifting paradigms

Bleeding during cardiac surgery, liver transplant, trauma and post partum hemorrhage are often multifactorial and these factors are dynamic as new factors crop up during the course of management. Conventional tests of coagulation offer information of a part of the coagulation system and also is time consuming. Viscoelastic point of care tests (VE POCTs) like rotational thromboelastometry, thromboelastogram and Sonoclot, are based on analysis of the viscoelastic properties of clotting blood and provide information for the entire coagulation pathway. In this comprehensive review being presented here, we have examined the pros and cons of VE POCTs including clinical, cost and survival benefits. The recommendations of the various guidelines regarding use of VE POCTs in various scenarios have been discussed. The review also tried to offer suggestions as to their optimal role in management of bleeding during cardiac surgeries, extracorporeal membrane oxygenation, left ventricular assist devices, liver transplant and briefly in trauma and postpartum hemorrhage.

Relation between aspirin resistance and thrombosis in high-risk pediatric patients following cardiac surgery: A prospective cohort study / 中国胸心血管外科临床杂志

@#Objective To determine the prevalence of aspirin (ASA) resistance in pediatric patients with congenital heart disease and evaluate whether postoperative thrombosis is associated with aspirin resistance. Methods A total of 52 patients undergoing high-risk congenital cardiac surgery were recruited in a prospective cohort study at Fuwai Hospital from August 2016 to December 2017. There were 29 males and 23 females with a median age of 8 months (6 d to 13 years). The response to aspirin was determined using the thromboelastography with platelet mapping (TEG-PM) system several days after administration. According to the arachidonic acid (AA) inhibition< 50% or not, they were divided into an ASA resistance group (n=14) and an ASA sensitivity group (n=38). Risk factors of ASA resistance were identified using univariate and multivariate analysis. Patients were monitored prospectively for three months for the development of a thrombosis event. Results Of 52 children analyzed, 14 (26.9%) were ASA resistance. The prevalence of thrombosis after ASA antiplatelet therapy was 5.9%. Dose escalation based on aspirin testing was performed in 3 of 14 patients, and the ASA sensitivity was observed in 1 patient. No correlation was found between ASA resistance and postoperative thrombosis (r=0.04, P=0.80). Conclusion Postoperative thrombosis is not associated with aspirin resistance in these patients. Our findings also suggest that resistance may be due to lack of aspirin doses, monitoring of aspirin therapy and consideration of dose adjustment or alternative agents for unresponsive patients.

Correlation study of gene polymorphism of CYP2 C19 and clopidogrel response after percutaneous translu-minal angioplasty and stenting in patients with ischemic cerebrovascular disease / 医学研究生学报

Objective There is little research on the relationship of gene polymorphism of CYP2C19 and clopidogrel response after percutaneous transluminal angioplasty and stenting ( PTAS) in patients with ischemic cerebrovascular disease.The study aimed to investigate the relationship between gene polymorphism and high on-treatment platelet reactivity ( HTPR ) after PTAS and 6 months of regular dual antiplatelet administration in patients. Methods A total of 145 Chinese patients treated with PTAS in our de-partment from January 2011 to March 2014 were enrolled in this study.According to the gene sequencing, patients were divided into wild-type group(CYP2C19*1/*1,69 cases) and mutation group(heterozygous mutation CYP2C19*1/*2 and homozygous mutation CYP2C19*2/*2, 76 cases).Patients received a 100mg/d aspirin and 75mg/d clopidogrel maintenance dose (MD) as dual anti-platelet therapy after PTAS.The clopidogrel inhibition effect was measured by thrombelastography ( TEG) system 6 months after PTAS. Routine cerebral artery digital subtraction angiography was applied to evaluate whether there was restenosis in stent and logistic regres-sion analysis was used to analyze the influential factors of HTPR after PTAS and clopidogrel adminstration. Results After 6 months'regular administration of clopidogrel after PTAS, the platelet adenosine diphosphate ( ADP ) receptor inhibition rates in wild-type group, heterozygous mutation and homozygous mutation group were respectively (58.43 ±21.98)%, (47.80 ±22.93)%, (37.53 ± 21.84)%.The platelet ADP receptor inhibition rate was significantly decreased compared with wild-type group(P=0.001).Carriers of at least one CYP2C19 loss-of-function ( LOF) allele had a higher frequency of clopidogrel HTPR (35.5% vs17.4 % for patients with and without LOF alleles, respectively;P=0.014) .Using multivariate logistic regression analysis, the carriage of CYP2C19 LOF alleles was an independent predictor of the post-procedure HTPR (OR=2.356, 95% CI:1.053-5.272, P=0.037).The rate of ISR was remarkably higher in patients with at least one CYP2C19*2 alleles compared with wild-type patients(11.8%vs 1.4%, P=0.019) . Conclusion In patients with ischemic cerebrovascular disease, the CYP2C19 LOF allele had significant impact on post-procedure clopidogrel HTPR and the prognosis of ISR after PTAS.

Efficacy of different anti-platelet aggregation regimens before percutaneous transluminal angioplasty and stenting / 第二军医大学学报

Objective To use thromboelastograph (TEG) technique for examining the platelet inhibition effect by aspirin and clopidogrel before percutaneous transluminal angioplasty and stenting (PTAS), so as to search for the optimal timing, dosage for clinical practice. Methods The clinical data of 93 patients were divided into 4 groups according to the aspirin history and different doses of aspirin before PTAS; the 4 groups were; non-medication history with aspirin+lower dose aspirin (aspirin 100 mg+clopidogrel 75 mg, Group 1), non-medication history with aspirin + higher dose aspirin(aspirin 300 mg+clopidogrel 75 mg, Group 2), medication history with aspirin+lower dose aspirin(Group 3), and medication history with aspirin+higher dose aspirin(Group 4). The blood samples were collected on day 1, 3 after anti-platelet aggregation drugs; TEG technique was used to detect arachidonic acid (AA)-induced inhibition rate of platelet aggregation and adenosine diphosphate (ADP) receptor-induced inhibition rate of platelet aggregation. Results For different time points; in group 1, the inhibition rates of platelet aggregation of aspirin and clopidogrel were significantly higher on day 3 (AA: \[89. 09 + 17. 42]%, ADP: \[57. 02 + 23. 97]%) as compared with those on day 1 (AA: \[82.24 + 22.25]%, ADP: \[49.62 + 25.44]%; P<0. 05); in group 3, the inhibition rates of platelet aggregation were also significantly higher on day 3 (AA: [95. 06 + 8. 05]%, ADP: \[47. 76 + 24. 95]%) than those on day 1 (AA: \[88.88 + 14.66]%, ADP: \[36.17 + 22.71)%]%; P<0. 05). For different doses: the AA-induced inhibition rates were not significantly different between group 1 and group 2 or between group 3 and group 4 on day 1 and 3. Conclusion Without aspirin history, the inhibitory effect of platelet aggregation of aspirin before PTAS for 3 d is better than that for 1 d, and there is no difference between those of lower and higher doses.

Evaluation of the efficacy of anti-platelet aggregation drugs in patients using thromboelastograph after percutaneous transluminal angioplasty and stenting / 中国脑血管病杂志

Objective: To detect the platelet inhibition of aspirin and Clopidogrel in patients after percutaneous transluminal angioplasty and stenting (PTAS) using a thromboelastograph (TEG) instrument in order to guide the individualized adjustment of anti-platelet aggregation drugs after PTAS. Methods: The clinical data of 65 patients with ischemic stroke or transient ischemic attack included from Nanjing Stroke Registry Program were analyzed retrospectively. Venous blood samples were collected at day 3 after PTAS. A TEG instrument was used to detect arachidonic acid (AA) -induced inhibition rate of platelet aggregation and adenosine diphosphate (ADP) receptor-induced inhibition rate of platelet aggregation. The AA pathway and ADP receptor-induced inhibition rate of platelet aggregation, as well as the response differences of the patients between aspirin and clopidogrel therapy were compared. Results: Circled digit oneThe inhibition rate (80 ± 28%) of aspirin for the AA pathway was significantly higher than that (53 ± 31%) of clopidogrel for the ADP receptor pathway (P < 0.01). Circled digit twoOf the 65 patients, the therapeutic effects in 45 (69.2%), 8 (12.3%), 7 (10.8%) and 5 (7.7%) patients were good, effective, low response, and ineffective in the aspirin group, and those in 19 (29.2%), 14 (21.5%), 23 (35.4%) and 9 (13.8%) were good, effective, low response, and ineffective in the clopidogrel group. Of those who had a good response to aspirin, 3 had no response to clopidogrel and 14 had low response to clopidogrel; of those who had a good response to clopidogrel, all responded well or effective to aspirin. Of those who had low response to clopidogrel, 4 had low response to aspirin, 5 had a good response to aspirin, and 14 had good results. The two efficacies had some relevance (χ2 = 33.311, P < 0.01). Circled digit threeA total of 53 patients had a good + effective response to aspirin, and 12 had low response + ineffective to aspirin, while 33 and 32 patients had good + effective and low response + ineffective to clopidogrel. There was significant difference in efficacy between the two drugs (χ2 = 15. 042, P < 0.01). Conclusion: Using TEG instrument to detect the inhibition rate of platelet aggregation in patients after PTAS is beneficial to guide the development of therapeutic scheme for individualized anti-platelet aggregation in clinical practice. The inhibitory effect of platelet aggregation of aspirin after PTAS is stronger than that of clopidogrel. The patients show differential responses to aspirin and clopidogrel therapy. Some patients who have low response to clopidogrel may respond well or may be effective to aspirin.

Hidroxietilalmidón (Hextend®) en solución electrolítica balanceada en el choque hipovolémico hemorrágico / Use of hetastarch in a balanced electrolyte solution - Hextend®- in the resuscitation of the patient in hypovolemic hemmorrhagic shock: review of the international literature

Hextend® is a preparation of hetilstarch in a balanced electrolyte solution that contains 143 mEq/L of sodium, 124mEq/L of chloride, 5 mEq/L of calcium 3 mEq/L of potassium 0.9 mEq/L of magnesium, 0.99 g/L of glucose and 24 mEq/L of lactate. It has a volume of distribution similar to blood volume which enables it to stay in the intravascular compartment until it is renally cleared or absorbed by the reticuloendothelial system. It shows a bimodal pattern of clearance with a half life during the first 8 hrs of its infusion of 4.2 hrs and during the 7 days following of 38.2 hrs. Hextend® is currently one of the preferred resuscitation solutions in the hypovolemic patient showing a better profile of effects over hemostasis and acid base status and conferring a better survival over similar patients resuscitated with crystalloids or other synthetic colloids. Hextend® provides an adequate fluid that is effective in the resuscitation of the trauma patient in hypovolemic hemorrhagic shock and promises to become the fluid of choice in the routine management of these patients. There is a need of more randomized prospective studies in the field of trauma using Hextend ® and its combination with the inflammatory cascade modifiers such as ethyl pyruvate among others.

Hextend® es una combinación de hetilalmidón balanceada en una solución de electrolitos que contiene 143 mEq/L de sodio, 124 mEq/L de cloro, 5 mEq/L de calcio, 3 mEq/L de potasio, 0,9 mEq/L de magnesio, 0,99 g/L de glucosa y 24 mEq/L de lactato. Posee un volumen de distribución equivalente al volumen sanguíneo manteniéndose en el compartimento vascular hasta ser excretado vía renal o absorbido por el sistema retículo-endotelial. Estas características le confieren un patrón farmacocinético bimodal con una vida media de 4,2 horas durante las primeras 8 hrs de infusión y de 38,2 h durante los primeros 7 días. Hextend® es actualmente una de las soluciones de reanimación con mejor perfil de efectos sobre la hemostasia y el equilibrio ácido base del paciente en choque hipovolémico y confiere un aumento de la sobrevida, comparado con controles resucitados con cristaloides u otros coloides sintéticos. Esta combinación de hetilalmidón en una solución amortiguadora electrolítica posee mínimos efectos sobre la función hemostática y plaquetaria por lo que actualmente es preferido frente a soluciones cristaloides y otros coloides utilizados en el pasado en la reanimación de pacientes politraumatizados en estado de choque hipovolémico hemorrágico. A su vez, promete transformarse en el fluido de elección en el manejo rutinario de estos pacientes. En relación al uso de este producto es imperativo realizar un mayor número de estudios prospectivos randomizados. La literatura internacional augura un esplendoroso futuro al uso de Hextend®, como también a su posible combinación con modificadores de la cascada inflamatoria, entre otros con el etil piruvato.

Perioperative Changes in Thromboelastogram in Elderly Patients Receiving Major Orthopedic Surgery / 대한마취과학회지

BACKGROUND: There is a high incidence of thromboembolism after major orthopedic surgery. However, more perioperative thromboembolic complications are expected after orthopedic surgery in geriatric patients due to the more offensive therapeutic measures and the increasing number of such patients with multimorbidity. Therefore it is important to investigate the perioperative blood coagulation status in detail. METHODS: Forty-five patients who were over 65 years old and scheduled for major orthopedic surgery were enrolled in this study. Patients with preoperative coagulation abnormalities, or receiving anticoagulants or antiplatelet medications were excluded. Preoperative thromboelastography (TEG), intraoperative TEG after blood loss equaling approximately 10% of the estimated blood volume, and postoperative TEG at the recovery room were measured and compared. RESULTS: During the operation, the R time and coagulation time (r + k) showed significant decreases, whereas the alpha angle, maximum amplitude (MA) and TEG index increased significantly (P < 0.05), indicating increased coagulability. The A60, CL30 and CL60 also increased, indicating decreased fibrinolysis (P < 0.05). These hypercoagulable findings were relieved after surgery to levels similar to those observed preoperatively. CONCLUSIONS: The intraoperative coagulability increased compared with the preoperative and postoperative period according to the TEG. This means that the intraoperative period is the period of most susceptibility to thromboembolic complications.

In Vitro and in Vivo Comparison of Antifibirinolytic Activity of Aprotinin and Tranexamic Acid Using a Thromboelastographic Method in Rabbits / 대한마취과학회지

BACKGROUND: Aprotinin and tranexamic acid are commonly used antifibrinolytics during liver transplantation, or cardiac surgery. However, it is not clear which drug is more effective to ameliorate the fibrinolysis. The aim of the study was to investigate the antifibrinolytic effect of both drugs at previously reported blood concentration and dose. METHODS: After inducing fibrinolysis by administering recombinant tissue plasminogen activator to rabbits, we checked the in vitro and in vivo antifibrinolytic effects at previously reported blood concentration and dose, and determined the minimum antifibrinolytic blood concentration. The previously reported blood concentration was 200 KIU/ml for aprotinin and 10 mcg/ml for tranexamic acid, and the previously reported dose was 4 mg/kg bolus plus 1 mg/kg/hr infusion for aprotinin and 10 mg/kg bolus plus 1 mg/kg/hr for tranexamic acid. RESULTS: In vitro experiment, there was effective antifibrinolytic action at previously reported blood concentration of aprotinin and the minimum antifibrinolytic blood concentration was 40 KIU/ml. For tranexamic acid, there was no antifibrinolytic action at previously reported blood concentration and the minimum antifibrinolytic blood concentration was 100 mcg/ml. In vivo experiment, there was antifibrinolytic action at previously reported dose of aprotinin and the minimum antifibrinolytic dose was 60% of previously reported dose. For tranexamic acid, there was no antifibrinolytic action at previously reported dose and the minimum antifibrinolytic dose was 10 times previously reported dose. CONCLUSION: The previously reported blood concentration and dose of aprotinin were greater and those of tranexamic acid were less than the minimum antifibrinolytic blood concentration and dose.

Changes in Thromboelastographic Findings after Bleeding-Induced Hemodilution in Patients Undergoing Radical Hysterectomy / 대한마취과학회지

BACKGROUND: Recent studies have produced conflicting results on the influence of hemodilution on the coagulation system. Furthermore, only a few clinical studies have been conducted regarding actual blood loss and associated hemodilution. The purpose of this study was to investigate changes in thromboelastograph (TEG) findings after moderate bleeding-induced hemodilution in patients undergoing radical hysterectomy. METHODS: 23 patients scheduled for radical hysterectomy were included. No patient had a preoperative coagulation abnormality or was receiving anticoagulant or antiplatelet medication. TEG findings 15 min after induction of anesthesia and after an estimated blood loss equaling 15% of the estimated blood volume were compared. Only crystalloid solution was administered until the second blood sampling for TEG analysis in order to produce a hemodilution state. RESULTS: After hemodilution R time, K time and coagulation time (r + k) showed significant reductions, and alpha angle and TEG index showed significant increases (P < 0.01), and increased coagulability. MA increased after hemodilution, but this was not statistically significant. A60 and CL60 also increased, showing decreased fibrinolysis (P < 0.05). CONCLUSIONS: Moderate bleeding-induced hemodilution increased coagulability according to TEG compared to pre-hemodilution findings. We recommend that the decision to replace coagulation factors and/or platelets should not be based on empirically derived, arbitrary standards.

The Effect of Low Dose Aprotinin on Postreperfusion Fibrinolysis in Liver Transplantation / 대한마취과학회지

BACKGROUND: The patients with end-staged liver failure are subjected to various and complex coagulopathies during liver transplantation. Particularly, fibrinolysis can occur preoperatively and is more prominent and aggravated right after reperfusion to the donated liver. It becomes the main cause of bleeding intraoperatively and postoperatively. We examined the effect of low dose aprotinin on the fibrinolysis and the transfusion amount of the packed red cell during operation. METHODS: We divided the patients into an experimental group, administrating aprotinin (n = 20) and a control group, administrating same volume of normal saline (n = 28). Heparinase-guided thromboelastograph (h-TEG) of preanhepatic 60 minutes was done as basic value. Then we administrated 1 million KIU aprotinin for 20 minutes and infused 0.25 million KIU /hr aprotinin for 3 hours of preanhepatic period in the experimental group. Just after the reperfusion to donated liver, another h-TEG of postanhepatic 10 minutes was done. We obtained CL 60 (clot lysis 60) and MA (maximum amplitude) among the TEG parameters and counted the total number of packed red cell transfused before and after the reperfusion period. RESULTS: The results showed that the experimental group had significantly higher value of CL 60 and MA in the h-TEG of postanhepatic 10 minutes and lower amount of packed red cell transfusion during the period after the reperfusion. CONCLUSIONS: The administration of low dose aprotinin during preanhepatic period reduced the activation of fibrinolysis and the total packed red blood cell transfusion after the reperfusion in liver transplantation.

Changes in Thromboelastographic Findings after Renal Transplantation in Patients with Chronic Renal Failure / 대한마취과학회지

BACKGROUND: Recent studies of thromboelastograph (TEG) findings have revealed that the hemostatic process is enhanced in uremic patients, suggesting an increased risk of thrombosis formation. The pathogenesis of hypercoagulability appears to be multifactorial in origin, and to involve associated lipid metabolism abnormalities. The purpose of this study was to investigate changes in TEG findings and lipid metabolism after renal transplantation. METHODS: 23 patients scheduled for renal transplantation were included. PT, PT-INR, and aPTT were used as laboratory blood coagulation tests, and concentrations of triglyceride and total cholesterol as indices of lipid metabolism abnormalities. TEG variables were measured before renal transplantation, and again at one and three weeks after transplantation, and then compared with pre-transplantation values. RESULTS: The pre-transplantation values of alpha-angle, maximal amplitude and A60 were above the normal ranges, showing hypercoagulability. They reduced significantly after successful transplantation suggesting that the hypercoagulable tendency is relieved upon correcting uremia (P < 0.05). The lipid metabolism study showed hypertriglyceridemia before transplantation. Triglyceride concentrations reduced significantly to normal levels after renal transplantation (P < 0.05), and were correlated with changes in alpha-angle, maximal amplitude, A60, TEG index, and LY30 (P < 0.01). CONCLUSIONS: Patients with chronic renal failure, associated with hypertriglyceridemia, as a form of lipid metabolism abnormality, showed hypercoagulability on TEG. With the correction of uremia after renal transplantation, the hypercoagulable findings are relieved and triglyceride levels reduce to normal. The normalization of lipid metabolism after renal transplantation might have a participatory role in relieving hypercoagulability.

The Effect of Magnesium Therapy on Thromboelastographic Findings in Patients with End Stage Liver Disease / 대한마취과학회지

BACKGROUND: Patients undergoing liver transplantation may be a group predisposed to hypomagnesemia and bleeding tendency. There is evidence that magnesium is a crucial constituent of the blood coagulation cascade and has a pro-coagulant activity. The purpose of this study was to investigate the effect of magnesium therapy on thromboelastograph (TEG) findings and other clinical parameters in patients undergoing liver transplantation. METHODS: 27 patients scheduled for liver transplantation were included. 1.5 g of magnesium sulfate was diluted in 100 ml of normal saline and infused over a period of 5 minutes to all patients. TEG findings immediately before and after magnesium infusion were compared. Total blood transfused and CaCl2 requirements in these patients were compared with those of a group of patients who received liver transplantation without magnesium therapy. RESULTS: K time and coagulation time (r + k) showed significant reduction, and MA, A60 and TEG index showed significant increases after magnesium therapy (P < 0.05). R time reduced and alpha angle increased after magnesium therapy, but these were not statistically significant. Less blood and CaCl2 was required by these patients (P < 0.05). CONCLUSIONS: Magnesium therapy significantly improved TEG findings of general hypocoagulability in end stage liver disease. It was also associated with a reduced amount of total blood transfused and CaCl2 required during liver transplantation.

Effect of Propofol Anesthesia on Blood Coagulation and Fibrinolysis: An Assessment Using Thromboelastograph at Clipping of Cerebral Aneurysms / 대한마취과학회지

BACKGROUND: Propofol may cause perioperative bleeding because it has an inhibitory effect on platelet aggregation and an accelerative effect on blood fibrinolysis in vitro. The aim of this study was to evaluate the perioperative effect of propofol anesthesia on blood coagulation and fibrinolysis with a thromboelastograph in patients undergoing clipping of cerebral aneurysms. METHODS: Fifteen patients who had cerebral aneurysms and no history of coagulation disorders were studied. Anesthesia was induced with a target controlled infusion of propofol to reach a calculated target blood concentration of 5ng/ml, and in addition, fentanyl 2ng/kg, lidocaine 1 mg/kg, esmolol 0.3 mg/kg and vecuronium 0.1 mg/kg were given intravenously. Anesthesia was maintained by propofol at target concentrations of 3 - 5ng/ml with nitrous oxide (67%) and oxygen (33%). The hemoglobin concentration, platelet count and a thromboelastogram were measured at before, during and after anesthesia. RESULTS: There was no significant difference in the perioperative hemoglobin concentration and platelet count. In terms of the thromboelastogram, r time (reaction time for clot formation) and k time (clot formation time) during and after anesthesia were shorter than those before anesthesia (P < 0.05), the alpha angle (rate of clot growth) during and after anesthesia was increased more than that before anesthesia (P < 0.05), and there was no significant difference in the perioperative fibrinolytic index. CONCLUSIONS: These results indicate that propofol anesthesia has no effect on anticoagulation and fibrinolysis in patients undergoing clipping of cerebral aneurysms in terms of the thromboelastogram, whereas, it showed a perioperative hypercoagulability. Therefore a clinical dosage of propofol may be used for neurosurgery without inhibition of coagulation.

Perioperative Changes of Blood Coagulation by a Thromboelastograph in Patients Undergoing Clipping of Cerebral Aneurysms / 대한마취과학회지

BACKGROUND: Patients undergoing brain surgery have a high risk of developing a number of perioperative coagulation disorders. Anesthesia and surgical stress may affect blood coagulation and fibrinolysis. The aim of this study was to evaluate perioperative changes in hemostatic parameters of patients undergoing clipping of cerebral aneurysms with a thromboelastograph (TEG) in combination with simple laboratory tests. METHODS: Twenty adult patients who had cerebral aneurysms and no history of coagulation disorders were studied. Isoflurane and N2O were used for all anesthetic proceedings. Preanesthetic, intraoperative (after skin incision and after clipping of cerebral aneurysms) and postanesthetic measurements included a TEG and simple laboratory tests. The TEG variables included r time (reaction time for clot formation), k time (clot formation time), alpha angle (rate of clot growth), MA (maximal amplitude of clot strength) and LY30 (fibrinolytic index). RESULTS: In simple laboratory tests, prothrombin time (PT) and partial thromboplastin time (PTT) at intraoperation and postanesthesia were longer than those at preanesthesia (p < 0.05). In the TEG, r and k time at intraoperation and postanesthesia were shorter than those at preanesthesia (p < 0.05). However the alpha angle at intraoperation and postanesthesia was longer than that at preanesthesia (p < 0.05). There was no significant difference in MA and LY30 except an increase in MA after the skin incision (p < 0.05) compared to the MA at preanesthesia. CONCLUSIONS: These results indicate a general hypercoagulability during and after a cerebral aneurysms operation in terms of TEG, although, the level of the PT and PTT can be at the upper limits within normal. Therefore perioperative use of coagulants in cerebral aneurysms may increase the risk of a thromboembolism because of accelerating blood coagulability. By early intraoperative and postoperativeevaluation of the hemostatic abnormality with a TEG, appropriate measures might be initiated to prevent postoperative complications due to hypercoagulability.

TEG Assessment of The Effect of Tranexamic Acid on Fibrinolysis during Open Heart Surgery / 대한마취과학회지

BACKGROUND: Activated fibrinolysis during cardiopulmonary bypass(CPB) is one of the causes of post CPB coagulopathy. Antifibirinolytics such as tranexamic acid have been administered prophylactically before CPB to decrease postCPB bleeding. However, their routinely application has been challenged as regarding it's thrombotic complication. This study was performed to evaluate the effect of tranexamic acid administered before CPB by thromboelastography. METHODS: 50 open heart surgical patients were randomly selected and devided into two groups, control(N=25) and tranexamic acid group(N=25). In tranexamic acid group. 125mg of tranexamic acid were singly infused before vena caval and aortic cannulation. All of parameters of thromboelastography (TEG) and fibrin degradation products measured before and after CPB were compared between two groups. RESULTS: There were no significant differences in fibrinolytic indexes of TEGs between control group and tranexamic group afte CPB. And there were also no changes in fibrinolysis index between before and after CPB in both groups. The concentration of FDP did not changed after CPB in both groups. CONCLUSIONS: It may be considered that prophylactic administration of tranexamic acid before CPB to reduce post-CPB bleeding would not be recommended routinely.